Release 10.1A: OpenEdge Getting Started:
Core Business Services

Firewall compatibility

For Internet-enabled AppServers using the AIA, OpenEdge supports the following options to maximize compatibility with firewalls:

TCP/IP port management.
Network Address Translation (NAT) and distributed configurations.
NameServer client port range value settings.
Direct connection to the AppServer without a NameServer to avoid UDP conflicts with firewalls.